Abstract

Background Impairments in cognitive functioning are common in
schizophrenia, and the degree of impairment may be associated with the
individual’s age at onset of the disorder.

Aims To examine the effect of age at onset on cognitive functioning
using the California Verbal Learning Test, sub-tests from the Wechsler Memory
Scale – Revised and sub-scales from the Wechsler Adult Intelligence
Scale – Revised among families with schizophrenia.

Method The effect of age at onset on cognitive function in 237
people with schizophrenia from a population-based sample was examined using
linear mixed effects models with family as the random effect, and age, gender,
chronicity of the illness and number of affected first-degree relatives as
fixed effects.

Results Impairment in verbal learning and memory was associated with
earlier disease onset. No association was found for working memory or IQ.

Conclusions In patients with early-onset schizophrenia, verbal
memory functions in particular should be taken into account in
neuropsychological evaluation and efforts at remediation.